The present invention relates to a material moving system in which capsules are transported within a pipeline. More particularly, the present invention relates to a method and apparatus for the loading and for the unloading of capsules and of groups or trains of capsules which comprise part of a continuous link of capsules in a pipeline.
For many years it has been known that fluid could be efficiently transferred by the use of pipelines. A fluid would be introduced into one end of a pipeline, pressure would be applied by means of pumps or gravity and the fluid would flow along the length of the pipeline to a desired destination. Solids may be transported by pipeline if the solids are first ground or crushed and then mixed with a suitable liquid to form a slurry. The slurry may be pumped through a pipeline, although the particles of solid within the slurry introduce additional problems in the apparatus required to pump and transport such material.
Most recently it has been discovered that there may be some energy efficiency in introducing the material to be transported into a capsule and then transporting the capsule through a pipeline. Systems exist whereby packaged or bulk material is introduced into wheeled capsules which are propelled through a pipeline by columns of air. Typically trains of, say, three or four capsules are formed and then transported through the pipeline by columns or "slugs" of air moving through the pipeline.
Two-directional flow is achieved through the use of a closed-loop system. Such a system could, of course, form a circle, or the like, with several terminals. Alternatively, a double pipeline could be built between two primary terminals with one pipeline representing a forward path and the other representing a return path. At each terminal a bypass system may be utilized to prevent the flowing air or fluid from being interrupted at terminals or stations.
As noted above, known capsule systems utilize trains of, say, three or four capsules separated by a column or "slug" of air. However, with prior art arrangements, the total load transported represents only 2% or so of the total pipeline volume. That is, a fully loaded capsule system in such a pipeline includes a volume of material which is only a very small percentage of the total volume of the pipeline.
There has been invented a system which utilizes a continuous train or link of capsules which completely fills the pipeline, which system has been made the subject of a co-pending application Ser. No. 925,514 filed on July 17, 1978, now abandoned.
The present invention relates to a system for loading and unloading capsules included within a substantially completely capsule-filled pipeline.
Prior art capsule systems appear to be limited to capsule speeds in the order of 10 to 12 meters per second. The speed of such capsules may be limited by the frictions between the capsules and the pipeline, the energy requirements for air pumps, and the like, necessary to move the capsules, and by the time required for loading and unloading of the capsules.
Recognizing the need for an improved pipeline capsule transportation system, it is, therefore, an object of the present invention to provide a pipeline capsule transportation system which facilitates the loading and unloading of capsules in a pipeline which contains a substantially continuous link of capsules.
According to one aspect of the invention, a pipeline capsule transportation system comprises: a first pipeline; a substantially continuous first link of capsules in said first pipeline; a second pipeline; a substantially continuous second link of capsules in said second pipeline; a station for unloading said first link of capsules, and for loading said second link of capsules, said station comprising: decoupling means for decoupling from said first link at a decoupling location in said first pipeline a predetermined number of capsules, said predetermined number of capsules defining a train; coupling means for coupling said train together with said second link at a coupling location in said second pipeline; conduit means for providing a path for said train between said decoupling means and said coupling means; valve means for isolating a zone in said conduit means from fluid communication with said first and second pipelines; and brake means for stopping said train in said isolated zone.
The system may include pump means for increasing a pressure in said isolated zone, with said valve means being cooperable with said pump means for creating a zone of relatively high pressure in the isolated zone to accelerate the train toward the coupling means.
The system may include first access means for placing a storage container in fluid communication with an inside of at least one capsule of the train when the train is in the isolated zone, the first access means being operable to empty at least one capsule comprising the train.
The system may further include second access means for placing a supply container in fluid communication with an inside of at least one capsule comprising the train when the train is in the isolated zone, the second access means being operable to fill at least one capsule comprising the train.
The system may conveniently include control means for controlling the decoupling means and the coupling means, to provide an uncoupling rate substantially equal to a coupling rate.
The system may include any conventional type of support means for supporting the length of capsules in the pipeline. In an embodiment of the invention, the support means may comprise magnetic support means of a conventional type for magnetically supporting the links of capsules in the pipelines.
In this embodiment of the invention, the decoupling means may, for example, comprise magnetic field producing means for producing a magnetic field which opposes a magnetic field of said magnetic support means. It will be appreciated, however, that any other form of conventional decoupling means may be employed.
The invention further extends to a method for loading and unloading a pipeline capsule transportation system comprising: conveying a first continuous or contiguous link of capsules in a first length of pipeline; selecting a predetermined number of capsules in the first length of pipeline, said predetermined number of capsules defining a train; uncoupling the train of capsules from the first continuous or contiguous link; accelerating the train of capsules along a first longitudinal pathway of pipeline; diverting the train of capsules into a transverse pathway of pipeline where the capsules may be loaded and unloaded; sealing a first and second end of the transverse pathway when the train of capsules is positioned therein; pressurizing the sealed transverse pathway; communicating the transverse pathway with a second longitudinal pathway; and coupling the train of capsules to a second continuous or contiguous link of capsules in a second length of pipeline.
According to a further aspect of the invention, there is provided a pipeline capsule transportation system for transporting a continuous link of capsules, the system comprising a first elongated pipeline along which a continuous link of capsules is to be transported, a loading station for loading capsules, and an unloading station for unloading capsules, the loading station comprising a handling zone, displacement means for displacing capsules from the handling zone to the first pipeline, and coupling means for coupling capsules entering the first pipeline to a trailing end of a continuous link of capsules moving along the first pipeline in use.
The continuous link of capsules may be transported along the pipeline by an suitable conventional means, but may conveniently be transported along the pipeline by the system which forms the subject of a co-pending patent application Ser. No. 925,514 filed July 17, 1978.
In one embodiment of the invention, the displacement means may comprise a charging conduit for charging capsules into the first pipeline, and acceleration means within the handling zone for accelerating capsules into the first pipeline.
In an example of this embodiment of the invention, the acceleration means may comprise valve means to isolate the handling means from the first pipeline, and pump means to create fluid pressure to accelerate capsules into the first pipeline when the valve means is opened.
In an alternative embodiment of the invention, the displacement means may comprise means for moving capsules from the handling zone to the pipeline, and acceleration means in the pipeline for accelerating such capsules in the pipeline prior to coupling with the continuous link of capsules moving in the pipeline.
Any suitable conventional means may be employed for moving the capsules from the handling zone to the pipeline. Thus, for example, the moving means may be in the form of mechanical moving means, magnetic moving means, gas pressure moving means, or the like.
In an example of this embodiment of the invention, the acceleration means in the pipeline may comprise an enclosure surrounding a length of pipeline and in fluid communication with the length of pipeline, and pump means for pumping a flow of fluid along the enclosure to accelerate capsules passing through the length of pipeline in the enclosure.
In an embodiment of the invention, the unloading station may comprise an unloading zone, decoupling means for decoupling capsules from a continuous link of capsules moving in the first pipeline, diverting means for diverting decoupled capsules to the unloading zone, and brake means to bring the capsules to rest in the unloading zone.
The diverting means may be of any conventional type, such as, for example, electromagnetic diverting means or displaceable mechanical diverting means.
The brake means may be of any conventional type.
The system may include a second elongated pipeline along which a continuous link of capsules is to be transported to the loading station, and the loading station may include decoupling means for decoupling capsules from a continuous link of capsules moving in the second pipeline, diverting means for diverting decoupled capsules to the handling zone, and brake means to bring the capsules to rest in the handling zone.
In an embodiment of the invention, the first and second pipelines may constitute a continuous loop of pipeline having the loading station at one location in the loop and having the unloading station at another location in the loop.
In this embodiment of the invention, the unloading station may include unloading means for unloading capsules while they are moving through the unloading station.
While various types of dynamic unloading means are known which could be applied to the unloading of capsules in the system of this invention, the unloading means may conveniently comprise inverting means for inverting the capsules while passing through the unloading station, and storage means for storing capsule charges discharged under gravity from inverted capsules in the unloading station.
Alternatively, for example, a reduced pressure zone may be provided in the unloading zone to effect unloading of capsules.
In an alternative embodiment of the invention, the first and second pipelines may constitute forward and return pipelines of the system with the loading station at one end and the unloading station at the other end, and with the unloading station corresponding substantially with the loading station in that it comprises an unloading zone, decoupling means for decoupling capsules from a leading end of a continuous link of capsules moving in the first pipeline, diverting means for diverting decoupled capsules to the unloading zone, brake means to bring capsules to rest in the unloading zone, displacement means for displacing capsules from the loading zone to the second pipeline, and coupling means for coupling capsules entering the second pipeline to a trailing end of a continuous link of capsules moving in the second pipeline.
The loading station may conveniently comprise a plurality of separate handling zones, and the unloading station may similarly comprise a plurality of separate unloading zones, with each of the handling and unloading zones having brake means and displacement means, and with each of the handling and unloading zones having diverting means associated therewith, the diverting means being selectively actuable to divert decoupled capsules into selected zones.
The invention further extends to a method of loading and unloading a pipeline capsule transportation system which includes the steps of: conveying a first continuous link of capsules in a first elongated pipeline; selecting a predetermined number of capsules from a leading end of the first continuous link of capsules, said predetermined number of capsules defining a train; uncoupling the train of capsules from the link; diverting the train into a handling zone of a loading station and bringing the train to rest in the handling zone; loading the capsules in the handling zone; displacing the train of loaded capsules from the handling zone to a second elongated pipeline wherein a second continuous link of capsules is being conveyed; coupling the train to a trailing end of the moving second link of capsules; and unloading the capsules at an unloading station between the first and second pipelines, the unloading station being at a point remote from the loading station.
The first and second pipelines may constitute return and forward pipelines of the system, and the method may include the steps of selecting a predetermined number of capsules from a leading end of the second link of capsules to define a train, uncoupling the train, diverting the train into an unloading zone of the unloading station, bringing the train to rest in the unloading zone, unloading the train, displacing the train into the first pipeline, and coupling the train to a trailing end of the first continuous link of capsules moving in the first pipeline.
In an alternative embodiment, the first and second pipelines may constitute a continuous loop and the first and second links of capsules may constitute a single continuous link of capsules, and the method may include the step of unloading capsules at the unloading station while the capsules are moving through the unloading station.
The dynamic unloading of the capsules may be effected by various means. Thus, in one example, the capsules may be unloaded dynamically by the capsules having openings which are normally directed upwardly, and by inverting the capsules in the unloading zone to discharge capsule contents under gravity, by applying a reduced pressure above the capsules to cause discharge of capsule contents, or the like.
Where the capsules are to be unloaded dynamically by inverting them, the capsules may be inverted by various conventional methods.
Thus, for example, the unloading zone may include biasing wheels arranged to engage with each capsule entering the unloading zone to progressively invert the capsules as they move along the unloading zone and thereafter to progressively restore the capsules to their normal upright condition.
In an alternative example, the inverting means may be provided by each capsule having a radially projecting inverting flange and by the unloading zone having a helical type groove to cooperate with the inverting flange to progressively invert the capsules as they move through the unloading zone, and then to progressively restore the capsules to their normal upright condition as they leave the unloading zone.
Embodiments of the invention are now described by way of example with reference to the accompanying drawings.